Item of footwear

ABSTRACT

An item of footwear and a method of modifying an existing item of footwear is provided that is compact, lightweight, resilient and stable. The item of footwear includes a sole; and a fibre reinforced shank extending along a length of the sole, to provide rigidity to the sole.

TECHNICAL FIELD

The present invention relates to items of footwear. The item of footwear may comprise a sandal, dress shoe, a walking shoe, an orthopedic shoe, a running shoe, or any other type of footwear.

BACKGROUND ART

It is well established that a person's feet are the foundation of their body. The feet, if correctly positioned, help control the person's centre of balance and alignment of lower and upper body skeleton. Correct alignment influences the pelvis and spine, and can thus help reduce problems associated with the lower back, spine and nervous system.

Previous attempts have been made to make shoes that help correctly position the feet of the wearer, however have been unsuccessful. In particular, attempts have been made at stiffening shoes through the use of a large shank in the sole of the shoe, to provide support and to prevent the shoe from twisting during use.

A problem with such shoes of the prior art is that they are bulky. In particular, a thickness of the sole must be increased to accommodate for the large shank, resulting in a heavy shoe, which renders this type of shank unsuitable for many purposes, including as running shoes.

A further problem with such shoes of the prior art is that the sole is prone to break at an edge of the shank. In particular, cracks form in the sole of shoes along an edge of the shank, particular in the front of the sole where the shoe is most flexible.

Further attempts were made at decreasing impact when walking through the use of rocker sole shoes, which were popularized in the late 1990s and 2000s. These shoes generally have rounded heels and a much thicker-than-normal sole. These shoes were marketed as fitness shoes and made claims they would strengthen muscles.

These rocker sole shoes were, however, found to lack stability and sideways control, and several manufacturers of these shoes were sued for making false claims in relation to their shoes. In short, these rocker sole shoes do not provide adequate support to the wearer.

As such, there is a need for an improved shoe.

It will be clearly understood that, if a prior art publication is referred to herein, this reference does not constitute an admission that the publication forms part of the common general knowledge in the art in Australia or in any other country.

SUMMARY OF INVENTION

The present invention is directed to shoe, which may at least partially overcome at least one of the abovementioned disadvantages or provide the consumer with a useful or commercial choice.

With the foregoing in view, the present invention in one form, resides broadly in an item of footwear including:

-   -   a sole; and     -   a fibre reinforced shank extending along a length of the sole to         provide rigidity to the sole.

Preferably, the item of footwear is a shoe.

Preferably, the fibre reinforced shank is provided within the sole.

Preferably, the item of footwear comprises a straight last shoe. Suitably, the sole has substantially straight longitudinal sides.

Preferably, the shank is reinforced by carbon fibre. Suitably, the shank is formed of carbon fibre reinforced polymer.

Preferably, the shank is configured to store kinetic energy from a one stage of a gait cycle, and use the kinetic energy in another stage of the gait cycle.

Preferably, the shank is disposed between an upper portion of the sole, and a lower portion of the sole. Suitably, the upper portion of the sole and the lower portion of the sole both extend along an entire length of the sole.

The shank may be glued between the upper and lower portions of the sole. Alternatively, the sole may be moulded with shank in place.

Preferably, the shank has a thickness of about 1 mm or less.

Preferably, the shank extends across a width of the sole.

Preferably, the item of footwear includes a heel counter, which extends upwardly from the sole. The heel counter may be moulded together with the sole. Alternatively, the heel counter may be sewn into an upper of the shoe.

Preferably, the shank includes a heel portion and a toe portion, and is curved upwards at the toe portion.

Preferably, the shank is curved upwards from a central portion of the shank to opposing ends of the shank.

Preferably, the shank includes a step in width at a boundary between the heel portion and the toe portion. Suitably, the toe portion is wider than the heel portion.

Preferably, the shank is curved upwards from a central portion of the shank to opposing sides of the shank.

The sole may include a plurality of recesses. Suitably, the plurality of recesses are defined by the outer sole.

In yet another form, the invention resides in a method of modifying an existing item of footwear including:

-   -   removing a lower portion of a sole of the item of footwear;     -   attaching a fibre reinforced shank to the remaining sole of the         item of footwear, such that the shank extends along a length of         the remaining sole to provide rigidity to the sole; and     -   attaching a further sole portion to an underside of the shank.

Any of the features described herein can be combined in any combination with any one or more of the other features described herein within the scope of the invention.

The reference to any prior art in this specification is not, and should not be taken as an acknowledgement or any form of suggestion that the prior art forms part of the common general knowledge.

BRIEF DESCRIPTION OF DRAWINGS

Various embodiments of the invention will be described with reference to the following drawings, in which:

FIG. 1 illustrates a side view of a base of a shoe, according to an embodiment of the present invention;

FIG. 2 illustrates a bottom view of the shoe of FIG. 1, according to an embodiment of the present invention;

FIG. 3 illustrates a sectional cut away view of the shoe of FIG. 1 along axis A-A of FIG. 2;

FIG. 4 illustrates a top view of the shank of the shoe of FIG. 1, according to an embodiment of the present invention;

FIG. 5 illustrates a sectional view of the shank of FIG. 4 along axis B-B of FIG. 4;

FIG. 6 illustrates a front view of shank of FIG. 4;

FIG. 7 illustrates a cross sectional view of the shank of FIG. 4 along axis C-C of FIG. 4;

FIG. 8A illustrates a heel-strike stage of a gait cycle with reference to the shoe of FIG. 1, according to an embodiment of the present invention;

FIG. 8B illustrates a mid-stance stage of the gait cycle; and

FIG. 8C illustrates a heel-off stage of the gait cycle.

Preferred features, embodiments and variations of the invention may be discerned from the following Detailed Description which provides sufficient information for those skilled in the art to perform the invention. The Detailed Description is not to be regarded as limiting the scope of the preceding Summary of the Invention in any way.

DESCRIPTION OF EMBODIMENTS

FIG. 1 illustrates a side view of a base of a shoe 100, according to an embodiment of the present invention. As discussed in further detail below, the shoe 100 includes a full length carbon fibre shank moulded inside the sole, which prevents unwanted flex in the shoe 100 and allows complete biomechanical control of the foot and ankle enabling a consistent and effective gait cycle.

The shoe 100 includes a sole 105, which is curved to provide a rocker that assists the wearer in walking when the front portion of the foot is lowered and the heel is lifted. The rocker of the sole 105 enables a naturally smooth follow through motion when walking or running, and reduces the ground reaction force that is exerted on the body when compared to other footwear.

The sole 105 includes a lower sole portion 105 a, which is in contact with the ground when in use, an upper sole portion 105 b, and a carbon fibre shank 110 disposed between the lower sole portion 105 a and the upper sole portion 105 b. The upper sole portion 105 a and the lower sole portion 105 b extend along an entire length of the sole 105.

The carbon fibre shank 110, described in further detail below, is lightweight and compact, and provides rigidity to the sole, while retaining limited flexibility. The shank 110 extends substantially along an entire length and width of the sole 105. As such, there are no weight bearing areas of the sole 105 unsupported by the shank 110, which prevents cracking to the sole 105 that would otherwise occur at edges of the shank 110.

The shoe further includes a heel counter 115, which extends upwardly from the sole 105, and is moulded together with the sole. The heel counter 115 extends around the heel providing a medial (inside) and lateral (outside) border to the heel. As such, the heel counter 115 supports and limits movement of the heel, and positively positions the heel and ankle in the shoe 100.

In other embodiments, not illustrated, the heel counter 115 is formed independently of the sole 105. In such case, the counter 115 may be stitched or glued into an upper of the shoe 110, and held in place by the upper.

The heel counter 115 extends laterally and medially to the proximal of the metatarsal heads.

The heel counter 115 may be formed thermoplastic, carbon fibre or any other suitable material.

The sole 105 is preferably made of composite materials or plastics. The shank 110 may be glued between the upper and lower portions 105 a, 105 b, or moulded with shank 110 in place. As an illustrative example, the shank 110 may be held in place by pins, by magnets or any other suitable means, as the upper and lower portions 105 a, 105 b are moulded around the shank 110.

The lower sole portion 105 a includes a bevelled lower edge 120, which provides a smooth transition between a lower surface and a side of the sole 105. The smooth transition can help soften an impact of the shoe 100 against the ground, particularly when accidently impacting the ground on an angle, while providing an aesthetically pleasing shoe design.

FIG. 2 illustrates a bottom view of the shoe 100, according to an embodiment of the present invention.

The sole 105 has substantially straight sides 205 which prevents the tendency of the foot (and shoe 100) to rotate inwardly or outwardly. In particular, the shoe 100 has a straight last, which distributes ground reaction forces both medially and laterally, and is wide, which makes the shoe 100 more stable.

In particular, the direction of ground reaction force is determined by the shape of the last of the shoe 100. The ground reaction force is the upward pressure from the foot and produces movement at each lower extremity joint (ankle, knee and hip). The ground reaction force is equal in magnitude and opposite in direction to the force that the body exerts on the supporting surface through the foot each time your foot strikes the ground. The magnitude and direction of the ground reaction force correlates with the stability of the footwear, and the straight last of the shoe 100 provides greater stability and thus decreased ground reaction force to the wearer.

While the sole is illustrated as a universal sole that is symmetrical, the skilled addressee will readily appreciate that left and right soles (and thus shoes) may be made that are not symmetrical, as is typical for retail shoes.

The sole 105 may include a plurality of recesses, not illustrated, to reduce the weight of the shoe 100 and help guide flexibility in the sole. In such case, the apertures would typically extend partway into the lower sole portion 105 a only, and thus a lower side of the shank 110 would protected by the lower sole portion 105 a.

FIG. 3 illustrates a sectional cut away view of the shoe 100 along axis A-A of FIG. 2. As previously, mentioned, the shank 110 extends along a length of the sole 105, and provides the shoe with stiffness and rigidity, both along a length and width of the shoe 100.

FIG. 4 illustrates a top view of the shank 110, according to an embodiment of the present invention. The shank 110 includes a heel portion 405, corresponding to a heel portion of the shoe 100, and a toe portion 410 corresponding to a toe portion of the shoe 100.

The shank 110 is formed of carbon fibre reinforced polymer. In particular, layers of carbon fibre may be woven, and laid upon each other with a resin or thermoplastic to form the shank 110. However, the skilled addressee will readily appreciate that other fibre reinforced materials may provide a suitably rigid and lightweight shank.

The shank 110 has a thickness of about 3 mm or less. This provides a lightweight construction, while providing strength to the shoe 100. In preferred embodiments, the shank 110 has a thickness of about 2 mm or less, and in even more preferred embodiments, the shank 110 has a thickness of about 1 mm or less.

A side of the shank 110 includes a step 415 between the heel portion 405 and the toe portion 410. The step 415 corresponds to a step of the upper sole portion 105 b, and enables a rigidity of the shank to vary along the length of the shoe 100, even when the shoe has a straight last. The toe portion 410 is wider than the heel portion 405, which provides additional rigidity to the toe portion 410 when stepping forward.

As best illustrated in FIG. 5 and FIG. 6, the shank 110 is curved upwards at the toe portion 410. This enables the shank 110 to conform to the curve of the rocker sole 105, and provide a “spring” in the shoe 100 when walking.

Similarly, as best illustrated in FIG. 6 and FIG. 7, the shank 110 is also curved upwards from a central portion 705 of the shank 110 to opposing sides 710 of the shank 110. This helps prevent pronation (inward) and super-nation (outward) rolling of the feet, ankles or knees while standing, walking or running by providing lateral support to the shoe 100.

The contoured full length carbon fibre shank 110 helps reform the rocker sole shape when body weight is applied or withdrawn giving the footwear far greater strength and wear through evenly balanced body weight and pressure distribution.

According to alternative embodiments, not illustrated, the shank 110 may be substantially flat, may be curved along a length of the shank 110 only, or curved along a width of the shank 110 only.

FIG. 8A-FIG. 8C illustrates a gait cycle with reference to the shoe 100, according to an embodiment of the present invention. In particular, the kinetic energy storage properties of the shank 110 are illustrated with reference to the gait cycle, which provides a balanced and controlled naturally smooth follow through motion from heel to toe.

FIG. 8A illustrates heel strike (initial contact) stage of the gait cycle. As the heel of the shoe 100 contacts the ground 805, the heel provides stability and correct positioning of the shoe 100 onto the ground 805. As this stage, downward pressure is applied to a rear of the shank 110, as illustrated by arrow 810 a.

FIG. 8B illustrates a mid-stance stage of the gait cycle. As the shoe 100 rotates forward, weight bearing forces (body weight) spreads across the shank 110, and downward pressure is applied to a rear of the shank 110, as illustrated by arrow 810 b, and a front of the shank 110, as illustrated by arrow 810 c. As a result, the shank 110 flexes along a length of the shank 110.

FIG. 8C illustrates a heel-off (propulsion) stage of the gait cycle. As the shoe 100 rotates further forward, weight bearing forces move forward along the shank 110, and downward pressure is applied to a front of the shank 110 only, as illustrated by arrow 810 d. As the weight is moved from a rear of the shank 110, the shank 110 reforms into its original shape, applying upward pressure to a rear of the shank 110, as illustrated by arrow 810 e.

The shank 110 essentially stores kinetic energy from the mid-stance stage, which is then used in the heel-off stage to propel the shoe forward. This provides a naturally smooth follow through motion, utilising minimal energy, and can minimise aggravation, stress, wear and tear to the wearer's feet, ankles, knees, lower back.

The kinetic energy storage characteristics of the shank 110 can not only assist users in walking, but can also be used to assist users when running, standing and moving around generally, and can even be of assistance to athletes and sportspeople.

While only a base of the shoe 100 is illustrated, the skilled addressee will readily appreciate that an upper may be attached to base. Alternatively, the base may be configured to receive straps to form a sandal.

Furthermore, the shoe 100 may be adapted to suit people with feet problems, or for a specific purpose, such as a running shoe, walking shoe, and the like. Similarly, the shoe may be adapted to suit people that are on their feet significant parts of the day, such as nurses and the like.

The shoe 100 may be orthotic friendly, and thus may be configured to receive orthotics, which may be glued or otherwise attached to an inside of the shoe 100. This is particularly useful when the shoe is used for medical purposes, but may also be useful when improving the posture of the wearer.

The shoe 100 is lightweight and has improved bounce back characteristics (ground reaction force) and decreased midsole break down (upward pressure from the foot), which makes the shoe particularly useful when walking or running.

According to certain embodiments of the present invention, an existing shoe may be modified to include the carbon fibre shank. In particular, part of the sole of the shoe may be removed, and the shank may be glued to the remaining sole. A lower sole may then be glued to the bottom of the shank. The shoe may have a similar appearance to what it had prior to modification. Alternatively, a substantially flat sole may be modified to form a rocker sole.

This enables existing footwear to be modified to suit the particular needs of an individual, which may reduce manufacturing cost, and provide a larger range of shoes which may form the basis for a shoe according to the present invention.

Advantages of embodiments of the invention include an ability to provide complete biomechanical control of the wearer's foot and ankle enabling a consistent and effective gait cycle. The shoe 100 provides a balanced and controlled follow through motion from heel to toe when the wearer's foot strikes the ground, and reduces impact, energy, and motion requirements of the foot. Furthermore, the shoe allows the wearers body weight to be evenly distributed throughout their lower and upper body skeleton to minimise aggravation, stress, wear and tear to your feet, ankles, knees, lower back and spine while standing, walking or running.

Such biomechanical control enables optimal heel strike, mid foot biomechanical control as well as fore foot biomechanical control, and thus includes controlling throughout the gait cycle. Such movement within the foot and ankle influences the ability of the lower limbs to control or reduce weight bearing forces. It is thus important to distribute and dissipate compressive, tensile, shearing, and rotatory forces during the phase of the gait cycle.

Inadequate distribution of these forces could lead to abnormal stress and the eventual breakdown of connective tissue and muscle. The combined effect of bone, muscle, ligaments, and normal foot biomechanics will result in the most efficient control or reduction of weight bearing force in the lower limbs.

The full length carbon fibre shank prevents twisting (torsion control) all throughout the sole of the shoe, and help reform the rocker sole shape when body weight is applied and withdrawn giving the footwear far greater strength and wear through evenly balanced body weight and pressure distribution

According to certain embodiments, the carbon fibre shank 110 can be provided in a variety of levels stiffness. This enables the shoe to be customised to a variety of purposes, with different focus on control and performance. As an illustrative example, a stiff shank may be provided for full protection and control of the biomechanics of the foot to enhance the toe off phase of the gait cycle, for example for rehabilitation, and a semi stiff shank may be provided for high performance and sports, such as running or race walking.

According to certain embodiments, the shoe 100 may be configured to work with various types of arches and feet. In particular, the shoe 100 may be configured to work with a flat or low arch, a normal or medium arch, or a high arch/cavus. Similarly, the shoe may be configured to work with a medial longitudinal arch (the biggest and most recognisable arch, along the inner side of the foot), a lateral longitudinal arch (smaller arch along the outer side of the foot), and/or a transverse arch (arch across the front part of the foot, which because of its location can't be seen in action)

The shoes 100 may include a contoured cork and natural latex footbed for healthy feet to support the natural shape of the foot.

In the present specification and claims (if any), the word ‘comprising’ and its derivatives including ‘comprises’ and ‘comprise’ include each of the stated integers but does not exclude the inclusion of one or more further integers.

Reference throughout this specification to ‘one embodiment’ or ‘an embodiment’ means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases ‘in one embodiment’ or ‘in an embodiment’ in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more combinations.

In compliance with the statute, the invention has been described in language more or less specific to structural or methodical features. It is to be understood that the invention is not limited to specific features shown or described since the means herein described comprises preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims (if any) appropriately interpreted by those skilled in the art. 

1. An item of footwear comprising: a sole; and a fibre reinforced shank extending along a length of the sole to provide rigidity to the sole.
 2. The item of footwear of claim 1, wherein the fibre reinforced shank is provided within the sole.
 3. The item of footwear of claim 1, wherein the sole defines a rocker that assists the wearer with forward movement when a front portion of the shoe is lowered and a heel portion of the shoe is raised.
 4. The item of footwear of claim 1, wherein the item of footwear comprises a straight last shoe.
 5. The item of footwear of claim 4, wherein the sole has substantially straight longitudinal sides.
 6. The item of footwear of claim 1, wherein the shank is reinforced by carbon fibre.
 7. The item of footwear of claim 6, wherein the shank is formed of carbon fibre reinforced polymer.
 8. The item of footwear of claim 1, wherein the shank is configured to store kinetic energy from a one stage of a gait cycle, and use the kinetic energy in another stage of the gait cycle.
 9. The item of footwear of claim 1, wherein the shank is disposed between an upper portion of the sole, and a lower portion of the sole.
 10. The item of footwear of claim 9, wherein the upper portion of the sole and the lower portion of the sole both extend along an entire length of the sole.
 11. The item of footwear of claim 1, wherein the shank is glued between the upper and lower portions of the sole.
 12. The item of footwear of claim 1, wherein the sole is moulded with shank in place.
 13. The item of footwear of claim 1, wherein the shank has a thickness of 1 mm or less.
 14. The item of footwear of claim 1, wherein the shank extends across a width of the sole. 15-16. (canceled)
 17. The item of footwear of claim 1, wherein the shank comprises a heel portion and a toe portion, and is curved upwards at the toe portion.
 18. The item of footwear of claim 1, wherein the shank is curved upwards from a central portion of the shank to opposing ends of the shank.
 19. The item of footwear of claim 1, wherein the shank comprises a step in width at a boundary between a heel portion of the shank and a toe portion of the shank.
 20. The item of footwear of claim 1, wherein a toe portion of the shank is wider than a heel portion of the shank.
 21. The item of footwear of claim 1, wherein the shank is at least partly curved upwards from a central portion of the shank to opposing sides of the shank.
 22. A method of modifying an existing item of footwear comprising: removing a lower portion of a sole of the item of footwear; attaching a fibre reinforced shank to the remaining sole of the item of footwear, such that the shank extends along a length of the remaining sole to provide rigidity to the sole; and attaching a further sole portion to an underside of the shank. 